Apparatus for producing crimps in the form of helical loops



Feb. 17, 1970 v. H. SCHRADER ETAL 3,495,310

APPARATUS FOR PRODUCING CRIMPS IN THE FORM OF HELICAL LOOPS Filed Feb. 16. 1968 INVENTOR VICTOR H. SCHRADER DONA LD W. MCKINNEY ATTORNEY United States Patent 3,495,310 APPARATUS FOR PRODUCING CRIMPS IN THE FORM OF HELICAL LOOPS Victor H. Schrader and Donald W. McKinney, Wilmington, Del., assignors to Joseph Bancroft & Sons Co.,

Wilmington, Del., a corporation of Delaware Filed Feb. 16, 1968, Ser. No. 706,164 Int. Cl. D02g 1/12 US. Cl. 281.7 6 Claims ABSTRACT OF THE DISCLOSURE A crimping apparatus having a chamber with an opening at one end and having a rotating plug that extends into said opening and is mounted concentric with said chamber. The plug has a disclike upper surface and a longitudinal yarn passage having an opening in said disclike surface which is eccentric with respect to the axis of rotation of the plug. As the plug rotates, the yarn is pulled through the eccentric opening into the chamber by the drag of the mass of yarn contained in said chamber and is formed into a succession of annular loops the diameter of which depends upon the tension of the incoming yarn, the eccentricity of the guide opening, the rate of rotation of the plug, and the back pressure of the mass of yarn in the crimping chamber.

This invention relates to apparatus for crimping yarn and more particularly for effecting a crimp in the form of small annular loops in a crimping chamber.

An object is to provide novel and improved apparatus of the above type.

Another object is to provide novel and improved mechanism for advancing yarn in a succession of annular loops into the crimping chamber of a crimping apparatus.

Another object is to provide means for controlling the crimp effect in an apparatus of the above type. Various other objects and advantages will be apparent as the nature of the invention is more fully disclosed. v

In accordance with the present invention, the yarn is formed with an eccentrically disposed yarn guidefrom which the yarn is pulled into the chamber. As the disclike member rotates, the yarn drags againstthe previously formed loops in the chamber and forms helical. coils having a diameter correspondingto the. eccentricity of the opening.

The succession of loops is advanced along the crimping chamber against the back pressureof the mass of yarn therein to form a core of coiled yarn which issubjected to setting conditions as it advances through the chamber. p v

The back pressure is controlledby afchoke' member which engages the core of crimped yarn inadvance of the discharge end. A feeler member rests upon'the discharge end of the core and is connected to control the relative rate of input and withdrawal in a sense tomaintain the discharge end of the core at a predetermined level.

The yarn is thus set in the form of a helix, the coils of which produce a bulked effect and impart other desirable characteristics to the yarn. If the yarn ispulled out into temporary straight form for weaving or other processing, the bulked form is restored by subjecting the yarn to relaxing conditions. 7 I

The nature of the invention will be betterunderstood from the following description, taken in connection with the accompanying drawing in which a specific embodiment has been shown for purposes of illustration.

3,495,310 Patented Feb. 17, 1970 In the drawing:

FIG. 1 is a longitudinal section through a stutter crimper embodying the invention;

FIG. 2 is a transverse section taken on the line 22 of FIG. 1 but on a larger scale; and

FIG. 3 is a sectional view illustrating the choke and feeler mechanism for controlling the back pressure and the yarn feed.

Referring to the drawing more in detail, the invention is shown as embodied in a crimper comprising a block 10 which is secured to a suporting plate 11 by a series of bolts 12 and is formed with a central bore 13 in which a crimping tube 14 is seated. The tube 14 rests upon the top surface 15 of a tapered member 16 which rests upon a shoulder 17 at the lower end of the bore 13 in the block 10 and is formed with a nose 18 at its lower end which extends downwardly through said bore.

A cylindrical plug 20 is disposed axially of the tube 14 and is formed with a disclike upper surface 21 which fits within the nose 18 of the tapered member 16. The plug 20 is pressed into a pulley member 28 which is journalled in a ball bearing comprising an inner race 24 and an outer race 25 which is seated in a bore 26 in the plate 11 and is held in place by a ring 27. The pulley member 28 extends axially below the plate 11 and carries a groove 29 which receives a belt 30'.

The plug 20 is formed with a longitudinal hole 31, the upper end at least of which is eccentric with respect to the axis of the plug. Feed rolls 32 may be disposed below the plug to facilitate pulling the yarn 33 from a source such as a package, not shown, and to control the tension on the yarn in advance of the plug.

The feed rolls 32 may be driven from the same Source as the plug 20 at a ratio such that the yarn is supplied to the plug 20 at the same rate as the yarn is drawn through the plug into the crimping chamber. This ratio may be varied by suitable control mechanism, not shown, either manually or in response to a tension control arm 34, which is responsive to the tension of the yarn 33 between the feed rolls 32 and the plug 20 and is adapted to maintain the yarn under a predetermined tension as it is advanced to the plug.

A suitable choke is disposed in the tube 14 in advance of the discharge end of the core of packed yarn therein so as to provide the required amount of back pressure of the yarn against disclike surface 21 in the crimping chamber. A sufiicient back pressure is required in order to cause the rotating plug 20 to generate the required wiping action between the yarn which is fed through the passage 31 and the core of yarn held compacted in the chamber 14 to pull the yarn through hole 31 in the rotating plug and form the same into successive annular loops. This back pressure may, of course, be adjusted to meet the re quirements in any particular case.

The tapered portion 16 at the lower end of the chamber formed by the tube 14 serves to concentrate the back pressure in the end surface of the plug 20, and, also, reduce the possibility of filament entrapment in the clearance between the walls of the chamber and the rotating plug.

The choke is shown as comprising a bracket 35 pivoted at 36 between arms 37 of a clamp 38 which is adjustably secured to the tube 14 just above the top of the heater block 10. The pivoted bracket 35 carries a wire 40 which extends through a slot 41 in the tube 14 to bear against the side of the core of yarn in the tube at that point. The wire 40 is formed with a smooth loop portion 42 which provides a smooth surface in contact with the yarn and also extends downwardly beyond the pivoted bracket 35 to carry an arm 43 on which a weight 44 is threaded for adjustment along the arm so that the pressure exerted by the wire 40 on the core can be varied depending on the back pressure desired.

The arrangement is such that the wire 40 compresses the core against the opposite side of the tube 14 and thus forms a choke to retard the advance of the core, thus exerting a controlled back pressure on the core of yarn in the entire area between the point of contact of the wire and the rotating plug 20.

A sensing device is disposed on the tube 14 at a point beyond the choke 40. This device comprises a feeler wire 45 extending through a slot 46 in the tube 14 to rest on the top surface of the core at the level of its discharge point. This feeler wire 45 is pivoted at 47 to a microswitch 48 and engages a pin 49 which is adapted to open and close the switch. The switch 48 is mounted on a bracket 50 which is clamped to the tube 14 by a clamp 51 and is adjustable along the tube. The microswitch 48 is connected to control the ratio between the drive for the plug and feed rolls and the drives of the winder, not shown, by which the crimped yarn is extracted from the discharge end of the core of yarn of the tube 14. The feeler wire 45 rests lightly on the core so as not to exert appreciable pressure thereon. Hence, the portion of the core between the choke wire 40 and the feeler wire 45 is substantially unconfined. Hence, the core in this zone tends to open up and becomes more permeable to air so as to facilitate the initiation of the cooling step. Although a microswitch is shown it may be desirable to use a more sensitive control switch such as, for example, a mercury switch.

The crimped yarn is withdrawn from the top of the core through a ceramic eye 52 to a winder, not shown, which may be of the constant speed type.

In operation, assuming that the tube 14 is filled with a mass of previously crimped yarn or, in starting, that a mass of yarn or the like is in the tube, the yarn 33 is threaded through the hole 31 in the plug 20 so that its free end is in contact with the filler in the tube 14 and the plug 20 is driven at a relatively high speed by the belt 30. As the surface 21 of the plug 20 rotates, the eccentric hole 31 describes a circle about the axis of the plug. Due to the drag of the yarn or filler within the tube 14, the yarn is pulled through the hole 31 in the plug 20 at a rate determined by the rate of rotation of the plug, the eccentricity of the hole 31 and the back pressure of the core, and is formed into a series of annular loops which advance upwardly as a helical coil as successive loops are formed thereunder. The tube 14 is thus filled with a mass of yarn in the form of small coils, which in the case of a synthetic yarn are set into the yarn by suitable heat,

as from heater elements 58 in the block and by subsequent cooling of the yarn while the coils are held compacted in the tube 14.

The resultant yarn which is extracted from the tube 14 is in the form of a series of coils or loops of generally helical form.

Since the yarn is lightly packed in the area above the choke device and the feeler wire 45 rests lightly on the top of the core, the yarn is pulled from under the feeler wire under a minimum tension so that the crimp is not appreciably reduced. This is to be distinguished from the action of a weight or plug resting on the top of the core which would exert substantial pressure on the yarn which is pulled out from under the same and would tend to iron out the crimp and also cause excessive variations in the tension of the yarn as the yarn is withdrawn. Hence, the yarn produced by the apparatus of the present invention has improved crimp retentivity and uniformity. By the time the yarn is wound on the package, it has cooled below its setting temperature so that the crimp remains set in the yarn and is restored by the usual rebulking technique as by heating to a temperature somewhat below its original setting temperature.

What is claimed is:

1. Yarn crimping apparatus comprising a crimping chamber having an input opening, a rotatable member disposed in said opening, means rotating said member concentric with the axis of said chamber, said member having a longitudinal passage for yarn including a discharge opening which is eccentric with respect to the axis of rotation of said member, means maintaining a mass of yarn in said chamber to exert back pressure against the yarn being pulled from said discharge opening in said rotating member whereby the yarn is caused to form a succession of loops Which are advanced as a core of crimped yarn along said chamber to the discharge opening, said rotatable member comprising a plug journaled for rotation in said input opening and carrying a grooved flange to receive a driving belt.

2. Yarn crimping apparatus comprising a crimping chamber having an input opening, a rotatable member disposed in said opening, means rotating said member concentric with the axis of said chamber, said member having a longitudinal passage for yarn including a discharge opening which is eccentric with respect to the axis of rotation of said member, means maintaining a mass of yarn in said chamber to exert back pressure against the yarn being pulled from said discharge opening in said rotating member whereby the yarn is caused to form a succession of loops which are advanced as a core of crimped yarn along said chamber to the discharge opening, said crimping chamber including a tapered end portion terminating in said input opening.

3. Yarn crimping apparatus comprising a crimping chamber having an input opening, a rotatable member disposed in said opening, means rotating said member concentric with the axis of said chamber, said member having a longitudinal passage for yarn including a dis charge opening which is eccentric with respect to the axis of rotation of said member, means maintaining a mass of yarn in said chamber to exert back pressure against the yarn being pulled from said discharge opening in said rotating member whereby the yarn is caused to form a succession of loops which are advanced as a core of crimped yarn along said chamber to the discharge opening, and means for subjecting the yarn in said chamber to setting conditions.

4. Yarn crimping apparatus comprising a crimping chamber having an input opening, a rotatable member disposed in said opening, means rotating said member concentric with the axis of said chamber, said member having a longitudinal passage for yarn including a discharge opening which is eccentric with respect to the axis of rotation of said member, means maintaining a mass of yarn in said chamber to exert back pressure against the yarn being pulled from said discharge opening in said rotating member whereby the yarn is caused to form a succession of loops which are advanced as a core of crimped yarn along said chamber to the discharge opening, a choke member positioned to engage the side of the core of yarn in said chamber at a point in advance of the discharge end thereof and to exert transverse pressure for impeding the advance of the core and thereby causing the core to exert a selected back pressure at said input opening.

5. Yarn crimping apparatus comprising a crimping chamber having an input opening, a rotatable member disposed in said opening, means rotating said member concentric with the axis of said chamber, said member having a longitudinal passage for yarn including a discharge opening which is eccentric with respect to the axis of rotation of said member, means maintaining a mass of yarn in said chamber to exert back pressure against the yarn being pulled from said discharge opening in said rotating member whereby the yarn is caused to form a succession of loops which are advanced as a core of crimped yarn along said chamber to the discharge opening, a sensing member disposed to sense the position of the leading end of the core of crimped yarn in said chamher and switch means controlled by said sensing member to control the relative rates of input to and withdrawal from said chamber.

6. Yarn crimping apparatus comprising a crimping chamber having an input opening, a rotatable member disposed in said opening, means rotating said member concentric with the axis of said chamber, said member having a longitudinal passage for yarn including a discharge opening which is eccentric with respect to the axis of rotation of said member, means maintaining a mass of yarn in said chamber to exert back pressure against the yarn being pulled from said discharge opening in said rotating member whereby the yarn is caused to form a succession of loops which are advanced as a core of crimped yarn along said chamber to the discharge opening, a feed roll disposed in advance of said rotating member and adapted to feed yarn thereto, and means responsive to the tension of the yarn between said feed roll and said rotating member for varying the drive ratio therebetween so as to maintain said tension substantially constant.

References Cited UNITED STATES PATENTS 3,178,794 4/ 1965 Carruthers 28-1 3,217,482 11/1965 Baer 19-66 XR 3,345,702 10/1967 Miedler et a1. 19159 DORSEY NEWTON, Primary Examiner 

